The phrase "and gather with a" is grammatically correct and can be used in written English.
It can be used when referring to the act of coming together with a group or individual for a specific purpose or activity.
Example: "We decided to meet at the park and gather with a few friends for a picnic."
Alternatives: "and assemble with a" or "and join with a".
After his testimony, General Petraeus will meet with the Iraqi ambassador to Washington, Samir al-Sumaidaie, and gather with a group of his West Point colleagues, Class of 1974.
The adults hunt and gather with a sense of play, and they have plenty of time left over for such leisure activities as gossiping, visiting friends in neighboring bands, making music, and in other ways playing (Gray 2009a; Sahlins 1972).
Their simple sportswear had a nice light touch, like a pale blue blouse cropped and gathered with a bit of elastic at the waist.
Saturday and gathered with a few late-shift colleagues in a weed-strewn parking lot across the street, law-enforcement officials say.
A small ice block sample was taken from each of the three sites and each ice block sample was melted in a small plastic tray, dried and gathered with a thin brush onto chartulae.
The process used sand and soda ash heated to a temperature of 2600 F and "gathered" with a large clay ball resembling a honey dipper.
We bought tickets a year ago, and gathered with friends, making a pact not to talk about the show until it was over.
Here, the family and sometimes the employer gather with a counselor, confront the addict and threaten to shun him or fire him if he doesn't enter a rehabilitation center.
Mantaray had a clubhouse were everyone could gather, with a TV and a bar.
Gather with a group of friends!
It was a very peaceful atmosphere, an unplanned celebration of diversity, no less a celebration of unity in all this diversity, as we were all longing for the same "resolution" and had all gathered with a common dream.
